Electric rail-bond.



' for the reception of the bolts 7 ,7 and 8,8

' UNITED STATES PATENT OFFICE.

BARTLETT H. THOMPSON, OF NORTH ADAMS; MASSrACHUSETTS, ASSIGN'OR' QE'ONE- HALF T GEORGE WALLACE, 0F WILLIAMSTOWN, MASSACHUSETTS;

ELECTRIC. RAIL-BOND.

Specification of Letters Patent.

Application filed March 8, 1913.

To all whom it may concern Be it known that I, BARTLETT H. THOMP- soN,a. citizen of the United States, residing at North Adams, in the countyof Berkshire and State of Massachusetts, have invented new and usefulImprovements in Electric Rail-Bonds, of which the following is aspecification. f

My invention relates to electric rail bonds and consists of a,conducting device adapted to be located within recesses or cavitiesformed in the tread portion of the rails where they are joined together,the device being constructed so as tobe maintained in operative relationwith the rails under the varying conditions of contraction andexpansion.

One of the objects accomplished by the invention is to locate thebonding device inside of the rail joint so as to afiord protectionagainst its destruction or derangement.

Another object is to provide compensating means to permit contractionand expan sion of the bond commensurate with the contraction andexpansion of the rails, which increases or decreases the space atthejoint.

-This self-adjusting feature of the bond is highly desirable.

Other objects and advantages will become apparent from the descriptionto follow.

In the accompanying drawing, illustrat ing the invention, Figure 1, is aside eleva-' tion of the parts of two railswhere joined together,portions of each being broken away and shown in section to clearlyillustrate the invention; Fig. 2, is a plan view of the bonding deviceand Fig. 3, is a detailed view of the insulating ring or washer whichforms a part of the device.

,In the drawing, like numerals of reference designate like parts.

1 1 and 2 designate the adjoining rails I which are provided with theusual tread portions 3 and 4. The body portions 5 and 6 are providedwith the usual bolt openings which secure the fish-plates 9, to connectthe rails at the joint.

The tread portions are provided with the cylindrical recesses 10 and 11arranged longitudinally and centered one with the other. The recess 11is made of greater depth than the other recess for a purpose which willbecome apparent from the description of con struction which follows. Theinterior ends. of these recesses are conical-shaped. Seated L in these..centeredrecesses and made of slightly less diameter so as to workfreely therein,.are the cylindrical pins or bolts '12 and 13, made ofany suitable conducting material. The pin 13 which is located in reclass11, is'correspondingly longer than the other pin. Said pins are formedwith conical-shaped ends Hand 15 and for a suitable distancelongitudinally their other ends, which adjoin, are reduced to formsemi-cylindrical portions 16 and 17. These portions are slightly less indiameterthan the major portions of the pins'and by this construction,are formed circumferential shoulders 18 and 19, on the pins,approximately an equal distance from the said adjoining ends. Theseshoulders are formed to-retain a spiral spring 20,of substantially thesame diameter as the major portions of the pins, which spring ismade ofany suitable conductingmaterial. The reduced portions 16 and 17 areinclosed by the said spring and the flat surfaces of the said portionsare arranged contiguously so as to slide longitudinally one against theother, under tension of the spring, when the'adjacent rail ends arecaused to be moved by contraction. The

action of the spring always holds the conical 1 ends of the pins incontact with their conical seats at the interior ends of the recesses.

A ring or washer 21 of any suitable, nonconducting material such asrubber or gutta- 'percha is provided with a central opening 22 ofsufficient diameter to permit the insertion of the pin 12.. When theabove described bonding device is in place, this insulating rlng orwasher, carried by the pin 12, is positionedbetween the contiguousendsof the rail.

Having thus fully described my invention,

what I claim as new and desire to secure by- Letters Patent is:

. 1. The combination with rails having concentric, longitudinal recessesformed, in"

their adjacent ends, of a bond for electricallv'connecting said rails,comprising a split conductor confined within the recesses and in'contactwith the rails, and 'means acting automatically for moving the sectionsof the conductor, one with each of the rails, when the latter are movedby force of contraction.

2. The combination with rails having concentric, longitudinal recessesformed in their adjacent ends, of a bond for electrically connectingsaidrails, comprising coacting pins of suitable conducting material,having slidable contact with one another, and positioned in saidrecesses in contact with the rails and means acting automatically, whenthe rails contract, for moving the said pins in relatively oppositedirections and for maintaining the said contact.

3. The'combination with rails having concentric, longitudinal recessesformed in their adjacent ends, of a bond "for electrically connectingsaid rails, comprising pins of suitable conducting material,havingslidable contact with one another and positioned in said recessesin contact with the rails and an expansible spring of conducting ma-.terial in engagement with and operating LOQEJLQQ pins to move the samein relatively opposite directions, when the rails contract, and tomaintain the said contact; and a ring or washer ofnon-conductingmaterial carried by one of said pins and interposedbetween the said rail-ends.

5. The combination with rails having concentric, longitudinal recessesformed in their adjacent ends, of a bond for electrically connectingsaid rails, comprising pins of suitable conducting material, positionedin saidrecesses in contact with the rails, said pins being constructedwith reduced semicylindrical portions forming shoulders and having,slidable contact with one another; a coiled spring of conductingmaterial surroundingsaid reduced portions and retained in place by saidshoulders, said spring operating upon the pins to move the same inrelatively. opposite directions when the rails contract, and to maintainthe said contact; and a ring or Washer of non-conducting materialcarried by one of said pins and interposed btwcen the said rail-ends.

In testimon whereof ll afiix my signature in presence 0 two witnesses.

BARTLETT H. THOMPSON.

, Witnesses:

WILLIAM OBRIEN,

JESSIE B. KERR.

